Browsing by Subject "Clinical Anatomy"

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    Circulus arteriosus cerebri: Anatomical variations and their correlation to cerebral aneurysms
    (2015) Du Toit, Francesca; Louw, Graham
    The anatomical structure of circulus arteriosus cerebri was first described by Thomas Willis in 1664. Many variations in the circulus arteriosus cerebri have since been reported. The extent to which anatomical variations within the circle influence aneurysm formation in a South African sample has not yet been established. The results of such a study would be of value to clinicians treating patients with vascular diseases. The aim of the study was to determine if there is a correlation between arterial variations in the circulus arteriosus cerebri and cerebral aneurysm formation. The brains of 39 cadavers at the Faculty of Health Sciences were removed and the circulus arteriosus dissected. In addition, 113 patients who underwent a MRI or MRA of the circulus arteriosus cerebri at the Department of Radiology at the Groote Schuur Hospital, Cape Town were included. For both of these samples the anatomical variations and any aneurysms present were documented. The external diameters of the arteries forming the circulus arteriosus cerebri were also measured. No aneurysms were found in the cadaver sample, thus the correlation could not be tested. In the sample of images from the 113 patients, 111 images showed one or more anatomical variation of the circulus arteriosus cerebri. Of these, 59 had one or more cerebral aneurysm and 52 had no aneurysms. Statistical analysis showed no significant correlation between cerebral aneurysms and anatomical variations in the circulus arteriosus cerebri for a South Africans ample. This is contradictory to what is seen in the literature. Further investigation is required to establish the reason why the results from this South African sample differ from the results reported in the international literature.
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    An investigation into the value of supplementing dissection of the human body with alternative resources: Perceptions of students and staff at the University of Cape Town
    (2017) Ramgoolam, Shakira; Louw, Graham J
    The purpose of this study was to explore the perceived value of supplementing the traditional cadaver dissection course at the University of Cape Town's Faculty of Health Sciences (UCT FHS) with alternatives in order to aid students in their learning of anatomy. The study aimed to collect information which could be used to provide insight into facilitating a deeper educational experience for students and teachers alike in the future with the aim of better retention of knowledge over time. The intention of the study was to obtain results which could potentially provide insight into the feasibility of adopting a contemporary view on anatomy education at UCT FHS and thus inform the anatomy course in the future by acquiring feedback directly from the students and staff of the university. Data was collected by way of a 22 question survey delivered to second to sixth year MBChB students as well as the staff and postgraduate students at UCT FHS. The survey was entirely voluntary. A total of 190 complete responses were collected. The results of the study indicate that both staff and students feel that the cadaver dissection course is an irreplaceable part of the curriculum, and if the faculty chose to use any technological alternatives to teach anatomy, that they should supplement and not replace traditional dissection. Furthermore, the study showed that the staff and students are comfortable with technology in general, and are open to the use of various technologies such as online material, virtual software, media sites, applications and the like in order to bolster their learning. These results may provide insight into the viability of adopting a contemporary view on anatomy education at UCT FHS and may thus inform changes to the anatomy curriculum in the future.
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    Lumbosacral transitional vertebrae morphology: a South African population
    (2021) Paton, Glen James; Louw, Graham J; Williams, Scott A; Nalla, Shahed
    Lumbosacral transitional vertebrae (LSTV) are defined as congenital anatomical variations, observed unilaterally or bilaterally, in which the transverse process of the last lumbar vertebra exhibits signs of dysplasia evident as increased craniocaudal height, with varying degrees of articulation or fusion to the ‘first' sacral vertebra. Such variations give rise to vertebral morphology that may display lumbar or sacral characteristics at the terminal lumbar spine, together with subsequent enumeration variation. The purpose of this study was to establish baseline data on the prevalence rates of LSTV and to describe the morphological characteristics (Type, subtype, frequency of side and spinal enumeration) of LSTV in the South African population. This study was subdivided into two main sections, namely Part 1: medical imaging appraisal and Part 2: osteological morphology appraisal. In Part 1, both retrospective and prospective cohort randomised sampling methods of data collection of medical images were used. The appraisal of the medical images included radiographs, magnetic resonance imagers and computerised tomography scans. Prevalence rates, utilising the Castellvi et al. (1984) classification, were established via radiographs only. Additionally, lumbar spine enumeration, namely lumbarisation and sacralisation, was made through the appraisal of lumbar radiographs. Images were obtained from medical radiology practices located at Groote Schuur Hospital in Cape Town, Western Cape Province and Charlotte Maxeke Johannesburg Academic Hospital in Johannesburg, Gauteng Province. The total imaging cohort included 3096 individuals of which 308 individuals (10%) were found to contain LSTV. Prevalence rates were further evaluated by subdivision of the three largest ancestries in South Africa. Ancestries were classified as African (n=1032), Mixed (n=1032) and European (n=1032). The prevalence of LSTV in the three ancestral groups was 10.5%, 9.3% and 9.9% respectively and the sex distribution was greater in females (52.1%) then in males (47.9%). The morphological assessment found the prevalence of LSTV by Type was Type II (67.9%) followed by Types III (27.6%) and IV (4.5%). The most frequent subtype by prevalence was Type IIA (41.9%) followed by Type IIB (26%), Type IIIB (21.8%), and Type IV (5.8%). Additionally, the frequency of side was bilateral (47.7%), left (26.6%), right (21.1%), and other (4.5%). Comparison of ancestry and spinal enumeration analyses established statistical significance for individuals of African-ancestry (67.0%) and Mixed-ancestry (72.9%) both of which demonstrated a greater affinity of prevalence for sacralisation (p=0.008), with a small effect size (V=0.178) over the European-ancestry subgroup (52.4%). Furthermore, a statistical significance with a medium effect size (V=0.256) was found in males (p=0.010) when comparing ancestry and spinal enumeration between sexes. In Part 2, a systematic search of the total cadaveric skeletal collection housed at the University of Witwatersrand (the Dart Collection of skeletons) yielded 1797 human skeletal specimens of between 21 and 65 years of age at time of death. One-hundred and fourteen skeletal remains were identified as containing LSTV. Damage and loss of vertebral elements resulted in a subset of 91 LSTV for study. A sex balanced control group cohort of 30 males and 30 females was selected at random from the Dart Collection for comparative analyses. A number of osteometric measurements were evaluated comparing the LSTV and control group cohorts. Numerous osteometric comparisons were statistically significant highlighting the many changes in lumbar and sacral morphology associated with LSTV. There are several original findings to emerge. Thisis the first study to establish the prevalence of LSTV in a large sample from the South African population, subdivided into the three largest ancestral groups. Novel findings associated with LSTV include iliolumbar articulation, bipartition of the sacral foramen, intra-articular vacuum phenomenon of accessory articulations of LSTV, enlargement of the contralateral TVP associated with Types III and IV LSTV, lumbar ossified bridging syndrome and a novel complex named by the researcher as the transverso-sacro-iliac articulation. Furthermore, the researcher has proposed three modifications to the Castellvi et al. (1984) classification, namely (1) that there should be a sub-classification of the Type IV LSTV into right and left nomenclature, (2) the inclusion of a new subtype of Type II LSTV morphology, a unilateral right or left iliolumbar articulation associated with contralateral Type IIA morphology, and (3) a modified morphological classification of LSTV based on the presence of an extended sacroiliac articulation either directly or via the transverso-sacro-iliac articulation. The latter effectively increases the size of the sacroiliac joint and is thought to increase spinopelvic stability. The transverso-sacroiliac articulation was demonstrated for all clinically significant LSTV Types (II-IV), both unilateral (right or left) and bilateral. Finally, this is the first study to incorporate an in situ and an ex situ study in the same population by examining spinal morphology of LSTV using medical images and skeletal remains for descriptive analyses.